A typical submerged oil well includes an electric motor driven down hole pump located at the lower end of a tubing string, with the upper end of the latter suspended from a tubing hanger removably supported in a well head. A Christmas tree array of valves is removably supported on the well head or a spool mounted on the latter.
A commonly used form of tubing hanger has an electrical conductor extending longitudinally therethrough, with the conductor on the upper and lower ends having connectors removably secured thereto that extend to a source of electric power and downwardly in the bore hole of the well to a submersible electric motor that drives a down hole pump. Due to the electrical conductor, the tubing string is supported from the tubing hanger in an off centered position thereon.
Periodically it is necessary to replace the connectors on the tubing hanger. Such replacement must be carried out under conditions where the oil well is at all times maintained under control.
A major object of the present invention is to provide a portable power operated assembly that may be removably secured in a fixed position relative to a well head to raise a tubing hanger and tubing string to permit electrical connectors and components to be replaced that are used in supplying electric power to an electric motor driven down hole pump, and without setting a tubing string pulling rig over the well.
Another object of the invention is to provide an assembly that may be removably secured to a blow out preventer secured to the well head, with the tubing hanger and portion of the tubing string being moved upwardly through the blow out preventer with the tubing string off centered relative thereto, and the tubing hanger being shifted laterally after the latter is above the blow out preventer to center the tubing string in the latter to permit the blow out preventer to be closed if necessary to maintain control of the well, and the tubing string being returned to an offset position in the well by reversing the above procedure.